A group of 100 Chicago medical students gathered outside of city hall to stage a die-in, demanding that Mayor Rahm Emanuel resign from office.

CBS News reports that the multiracial group, holding signs reading #WhiteCoats4BlackLives, laid outside of the building for 16 minutes—one minute for every time 17-year-old Laquan McDonald was shot last year.

“We’ve seen the dramatic differences in health outcomes for different populations in our city,” Rush Medical College student Josh Eloge told CBS. “And we’re not okay with the idea that some populations are more safe than others, and certainly not that it comes from places as high up as our mayor’s office.”

Last month, Chicago officials made the decision to release video footage from the October 2014 shooting death of McDonald. Police officers approached the teen for reportedly possessing a knife. Dash cam video shows McDonald walking away from police when former Officer Jason Van Dyke opens fire, shooting the teen 16 times.

More than one year after the shooting, officials made the decision to release the video. Van Dyke was arrested and charged with murder. Earlier this week, Emanuel took full responsibility for the shooting, but his apology prompted numerous protests with residents calling for his resignation.

“Even more so, [I am here] ti stand against obstruction of the law for the purpose of political gain,” Chicago College of Osteopathic Medicine Ashley Czworniak told CBS. “That is exactly what Rahm Emanuel did by suppressing the issue of Laquan McDonald’s death until after his re-election. I take issue with a powered official valuing Black lives enough to use them as pawns for the purpose of re-election, but not valuing them enough to be honest with them about the violence that happens in their own communities.”